I don't think the colorist in that image honestly wants to convey a blue wearing Batman, especially when in the years prior to that story the blue had been toned darker and darker, said to be black, but never went fully black. Blue has become a genre convention for Batman, even when it's acknowledged that the actuality is that it's black. You have Denny O'Neil and ever other comic writer-turned-novelist writing the cape and cowl black in their adaptations of major storylines like Knightfall and No Man's Land... despite the cape and cowl being blue(light blue in Knightfall, dark/midnight blue in No Man's Land) in the comics.

Do you honestly believe Batman is supposed to be running around in light blue cape and cowl? To scare criminals?